JP7495443B2 - Humidifier Reservoir - Google Patents

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of Australian Provisional Application No. 2016904769, filed November 22, 2016, each of which is incorporated by reference in its entirety herein.
2. Technology Background 2.1 Technology Field

The present technology relates to one or more of the detection, diagnosis, treatment, prevention and amelioration of respiratory related disorders. The present technology also relates to medical devices or apparatus and uses thereof.

2.2 Description of Related Art 2.2.1 The Human Respiratory System and Its Disorders The body's respiratory system facilitates gas exchange. The nose and oral cavity form the entrance to a patient's airways.

These airways contain a series of branching tubes that become narrower, shorter and more numerous the deeper they go into the lungs. The primary function of the lungs is gas exchange, allowing oxygen to enter from the air into the venous blood and carbon dioxide to leave. The trachea divides into the right and left main bronchi, which further divide into the terminal bronchioles. The bronchi constitute the conducting airways and do not participate in gas exchange. The airways further divide into the respiratory bronchioles and finally into the alveoli. Gas exchange takes place in the alveolar region of the lung, which is called the respiratory zone. See: 1999 pulmonary circulation, ...

A range of respiratory disorders exists. Particular disorders may be characterized by specific manifestations (e.g., apnea, hypopnea, and hyperpnea).

Examples of respiratory diseases include obstructive sleep apnea (OSA), Cheyne-Stokes respiration (CSR), respiratory failure, obesity hyperventilation syndrome (OHS), chronic obstructive pulmonary disease (COPD), neuromuscular diseases (NMD) and chest wall diseases.

Obstructive sleep apnea (OSA) is a form of sleep-disordered breathing (SDB) characterized by episodes such as closure or obstruction of the upper airway during sleep. It is the result of an abnormally small upper airway combined with the normal loss of muscle tone in the region of the tongue, soft palate and posterior oropharyngeal wall during sleep. The condition causes affected patients to pause breathing, typically for 30-120 seconds, sometimes as many as 200-300 times per night. This results in excessive daytime sleepiness, which can lead to cardiovascular disease and brain damage. The condition is common, especially in middle-aged, overweight men, but patients are asymptomatic. See U.S. Patent No. 5,339,993 (Sullivan).

Cheyne-Stokes respiration (CSR) is another form of sleep-disordered breathing. CSR is a disorder of the patient's respiratory regulator that is followed by alternating periods of waxing and waning ventilation, known as CSR cycles. CSR is characterized by repeated deoxygenation and reaeration of arterial blood. Because of the repeated hypoxia, CSR can be harmful. In some patients, CSR is associated with recurrent sleep arousals that cause severe insomnia, increased sympathetic activity, and increased afterload. See U.S. Patent No. 5,339,993 (Berthon-Jones).

Respiratory failure is a general term for respiratory disorders that refers to the inability of the lungs to take in enough oxygen or breathe out enough _CO2 to meet the patient's needs. Respiratory failure can include some or all of the following conditions:

Patients with respiratory failure (a type of respiratory insufficiency) may experience abnormal shortness of breath during exercise.

Obesity hypopnea syndrome (OHS) is defined as the combination of severe obesity and chronic awake hypercapnia in the absence of other known causes of hypoventilation. Symptoms include dyspnea, morning headache, and excessive daytime sleepiness.

Chronic obstructive pulmonary disease (COPD) encompasses any of a group of lower airway diseases that share certain common characteristics. These include increased resistance to air movement, prolongation of the expiratory phase of breathing, and a decrease in the normal elasticity of the lungs. Examples of COPD include emphysema and chronic bronchitis. Causes of COPD include chronic smoking (the primary risk factor), occupational exposure, air pollution, and genetic factors. Symptoms include dyspnea on exertion, chronic cough, and sputum production.

Neuromuscular diseases (NMD) is a broad term that encompasses numerous diseases and illnesses that impair muscle function directly through intrinsic muscle pathology or indirectly through neuropathology. Some NMD patients are characterized by progressive muscle damage that results in inability to walk, wheelchair confinement, difficulty swallowing, respiratory muscle weakness, and ultimately death due to respiratory failure. Neuromuscular disorders can be classified as rapidly and slowly progressive: (i) rapidly progressive disorders, characterized by muscle damage that worsens over months and leads to death within a few years (e.g., amyotrophic lateral sclerosis (ALS) and Duchenne muscular dystrophy (DMD) in teenagers); (ii) variable or slowly progressive disorders, characterized by muscle damage that worsens over years and only slightly reduces life expectancy (e.g., limb-girdle, facioscapulohumeral, and myotonic muscular dystrophies). Symptoms of respiratory failure in NMD include: increasing generalized weakness, difficulty swallowing, dyspnea on exertion and at rest, fatigue, drowsiness, morning headache, and difficulty concentrating and mood changes.

Chest wall disorders are a group of thoracic deformities that result in ineffective connections between the respiratory muscles and the rib cage. These disorders are primarily characterized by restrictive defects and share the potential for long-term hypercapnic respiratory insufficiency. Scoliosis and/or kyphoscoliosis can cause severe respiratory insufficiency. Symptoms of respiratory insufficiency include: dyspnea on exertion, peripheral edema, orthopnea, recurrent chest infections, morning headache, fatigue, poor quality of sleep, and loss of appetite.

A range of treatments are available to treat or ameliorate such conditions, and otherwise healthy individuals may also benefit from preventative treatments for respiratory disease, but these suffer from a number of deficiencies.
2.2.2 Treatment

A variety of therapies (e.g., continuous positive airway pressure (CPAP) therapy, non-invasive ventilation (NIV) and invasive ventilation (IV)) are used to treat one or more of the above respiratory disorders.

Continuous positive airway pressure (CPAP) therapy has been used in the treatment of obstructive sleep apnea (OSA). Its mechanism of action is that CPAP acts as a pneumatic splint, for example by pushing the soft palate and tongue forward or backward against the posterior oropharyngeal wall, which may prevent closure of the upper airway. Because treatment of OSA with CPAP therapy may be voluntary, patients may choose not to comply with treatment if they perceive the device used to deliver the treatment to be one or more of the following: uncomfortable, difficult to use, expensive, or aesthetically unappealing.

Non-invasive ventilation (NIV) provides ventilatory support to a patient through the upper airway to assist the patient in breathing by performing some or all of the respiratory function and/or maintaining adequate oxygen levels in the body. Ventilatory support is provided through a non-invasive patient interface. NIV is used in the treatment of forms of CSR and respiratory failure such as OHS, COPD, NMD, and chest wall disorders. In some forms, it can improve the comfort and effectiveness of these treatments.

Invasive ventilation (IV) provides ventilatory support to patients who can no longer breathe effectively on their own and may be provided using a tracheotomy tube. In some forms, the comfort and effectiveness of these treatments may be improved.
2.2.3 Treatment system

These treatments may be provided by a therapeutic system or device. Such systems and devices may also be used to diagnose a disease without treating it.

The treatment system may include a respiratory pressure therapy device (RPT device), an air circuit, a humidifier, a patient interface, and data management.

Another form of treatment system is a mandibular repositioning device.
2.2.3.1 Patient Interface

The patient interface may be used to provide the wearer with an interface to the respiratory appliance, for example by providing airflow to the airway entrance. Airflow may be provided via a mask to the nose and/or mouth, a tube to the mouth, or a tracheotomy tube to the patient's trachea. Depending on the therapy being applied, the patient interface may form a seal, for example with an area of the patient's face, to facilitate gas delivery at a pressure of sufficient dispersion with atmospheric pressure for therapy to be performed (e.g., at a positive pressure of about 10 cm _H2O relative to atmospheric pressure). In other forms of therapy, such as oxygen delivery, the patient interface may not include a seal sufficient to facilitate delivery of a gas supply to the airways at a positive pressure of about 10 cm _H2O .

Certain other mask systems may be functionally inadequate in this field. For example, masks that are purely decorative may not be able to maintain adequate pressure. Mask systems used for underwater swimming or diving may be configured to protect against water intrusion from higher external pressures and not maintain internal air at pressures higher than ambient.

Certain masks may be clinically unsuitable for use with this technology (e.g., if the mask blocks airflow through the nose and only allows airflow through the mouth).

In certain masks, the patient must insert part of the mask structure into their mouth and create and maintain a seal via their lips, which may be uncomfortable or impractical with this technique.

Certain masks may be impractical for use while sleeping (e.g., when sleeping on your side in bed with your head on the pillow).

There are multiple challenges in designing a patient interface. The face has a complex three-dimensional shape. The size and shape of the nose and head vary greatly between individuals. Because the head contains bone, cartilage and soft tissue, different regions of the face respond differently to mechanical forces; i.e., the chin or mandible may move relative to other bones of the skull. The entire head may move throughout the respiratory treatment period.

These challenges may result in one or more of the following: some masks may be intrusive, aesthetically undesirable, costly, poor fit, difficult to use, and uncomfortable, especially if the wear time is long or the patient is unfamiliar with the system. If the wrong size mask is used, this may lead to poor compliance, poor comfort, and poor patient outcomes. While masks designed specifically for aviators, as part of personal protective equipment (e.g., filter masks), SCUBA masks, or anesthesia administration masks may be tolerable for their intended use, such masks may be undesirably uncomfortable to wear for extended periods of time (e.g., hours). Such discomfort may result in poor patient compliance with treatment. This is especially true if the mask must be worn while sleeping.

CPAP therapy is highly effective in treating certain respiratory disorders if the patient complies with the treatment. If the mask is uncomfortable or difficult to use, the patient may not comply with the treatment. Because patients are often encouraged to clean their masks regularly, if the mask is difficult to clean (e.g., difficult to assemble or disassemble), the patient may not be able to clean the mask, which may affect patient compliance.

Masks for other uses (e.g., for aviators) may be unsuitable for use in treating sleep-disordered breathing, and masks designed for use in treating sleep-disordered breathing may be suitable for other uses.

For these reasons, patient interfaces for CPAP delivery during sleep form a distinct field.
2.2.3.1.1 Seal formation structure

The patient interface may include a seal-forming structure. Because the patient interface is in direct contact with the patient's face, the shape and configuration of the seal-forming structure may have a direct impact on the effectiveness and comfort of the patient interface.

The patient interface may be characterized in part according to the design intent of where the seal-forming structure engages the face in use. In one form of the patient interface, the seal-forming structure may include a first sub-portion for forming a seal around the left nostril and a second sub-portion for forming a seal around the right nostril. In one form of the patient interface, the seal-forming structure may include a single element that encloses both nostrils in use. Such a single element may be designed to rest, for example, on the upper lip region and nose bridge region of the face. In one form of the patient interface, the seal-forming structure may include an element that encloses the oral cavity region in use, for example by forming a seal on the lower lip region of the face. In one form of the patient interface, the seal-forming structure may include a single element that encloses both nostrils and the mouth region in use. These different types of patient interfaces may be known by various names by their manufacturers, such as nasal masks, full face masks, nasal pillows, nasal puffs, and oronasal masks.

A seal-forming structure that may be effective in one area of a patient's face may be inappropriate in another area due to, for example, different shapes, structures, variability, and sensitive areas of the patient's face. For example, the seal of swim goggles that rests on the patient's forehead may be inappropriate for use on the patient's nose.

A particular seal-forming structure can be designed for mass production so that one design will fit, be comfortable, and be effective for a wide range of different face shapes and sizes. To the extent there is a mismatch between the shape of the patient's face and the seal-forming structure of the mass-produced patient interface, one or both must be adapted to form a seal.

One type of seal-forming structure extends around the periphery of the patient interface and is intended to seal against the patient's face when force is applied to the patient interface with the seal-forming structure engaged against the patient's face. The seal-forming structure may include an air or fluid filled cushion, or may include a molded or formed surface of a resilient sealing element comprised of an elastomer such as rubber. With this type of seal-forming structure, if the fit is improper, a gap will develop between the seal-forming structure and the face, and additional force will be required to press the patient interface against the face to achieve a seal.

Another type of seal-forming structure uses a thin flap seal placed around the periphery of the mask to provide a self-sealing action against the patient's face when positive pressure is applied within the mask. As with the previous type of seal-forming portion, if there is poor conformity between the face and the mask, additional force may be required to achieve a seal or the mask may leak. Additionally, if the shape of the seal-forming structure does not conform to the shape of the patient, the seal-forming portion may fold or buckle during use, causing leakage.

Other types of seal-forming structures may include friction-fit elements that are inserted into the nostrils, for example, but some patients find these seal-forming parts uncomfortable.

Another form of seal-forming structure may use adhesives to achieve a seal. Some patients find it inconvenient to constantly apply and remove adhesives from their face.

A range of patient interface seal forming structures are disclosed in the following patent applications (assigned to ResMed Limited: U.S. Pat. No. 5,393,633; U.S. Pat. No. 5,493,633; U.S. Pat. No. 5,493,633).

One form of nasal pillow is found in the Adam circuit manufactured by Puritan Bennett. Another nasal pillow or puff is the subject of U.S. Pat. No. 6,399,433 (Trimble et al.), assigned to Puritan-Bennett Corporation.

ResMed Limited manufactures the following products that use nasal pillows: SWIFT® Nasal Pillows Mask, SWIFT® II Nasal Pillows Mask, SWIFT® LT Nasal Pillows Mask, SWIFT® FX Nasal Pillows Mask and the MIRAGELIBERTY® Full Face Mask. Examples of nasal pillows masks are described in the following patent applications assigned to ResMed Limited: U.S. Patent No. 5,393,663 (depicting, among other aspects, ResMed Limited's SWIFT® nasal pillows), U.S. Patent No. 5,393,663 (depicting, among other aspects, ResMed Limited's SWIFT® LT nasal pillows); U.S. Patent No. 5,393,663 and U.S. Patent No. 5,393,663 (depicting, among other aspects, ResMed Limited's MIRAGE LIBERTY® full-face mask); and U.S. Patent No. 5,393,663 (depicting, among other aspects, ResMed Limited's SWIFT® FX nasal pillows).
2.2.3.1.2 Positioning and stabilization

The seal-forming structures of patient interfaces used in positive air therapy experience corresponding forces from the air pressure that disrupt the seal. As a result, a variety of techniques are used to position the seal-forming structures and maintain a seal against the appropriate portion of the face.

In one technique, adhesives are used. See, for example, U.S. Patent No. 5,399,633. However, adhesives can be uncomfortable.

Another technique involves the use of one or more straps and/or stabilizing harnesses, many of which suffer from one or more of the following problems: poor fit, bulkiness, discomfort and awkwardness.
2.2.3.2 Respiratory Pressure Therapy (RPT) Devices

Respiratory pressure therapy (RPT) devices may be used to deliver one or more of the therapies described above, for example, by generating an air delivery flow to an airway inlet. This air flow may be pressurized. Examples of RPT devices include CPAP devices and mechanical ventilators.

Air pressure generators are known for a wide range of applications (e.g., industrial-scale ventilation systems). However, air pressure generators for medical applications have specific requirements that cannot be met by more common air pressure generators (e.g., medical equipment reliability, size and weight requirements). In addition, even devices designed for medical treatment may suffer from deficiencies related to one or more of the following: comfort, noise, ease of use, effectiveness, size, weight, manufacturability, cost and reliability.

One example of a special requirement for a particular RPT device is acoustic noise.

Table of noise output levels of conventional RPT devices (measured on only one sample at 10 _cmH2O in CPAP mode using the test method specified in ISO 3744).

One known RPT device used to treat sleep-disordered breathing is the S9 Sleep Therapy System (manufactured by ResMed Limited). Another example of an RPT device is a ventilator. Ventilators (e.g., the ResMed Stellar® series of adult and pediatric ventilators) can provide invasive and non-invasive independent breathing support for patients for a range of conditions, including but not limited to NMD, OHS, and COPD.

The ResMed Elisee® 150 ventilator and the ResMed VSIII® ventilator can provide invasive and non-invasive dependent respiratory support suitable for adult or pediatric patients for the treatment of multiple conditions. These ventilators provide volumetric and pressure ventilation modes with single or dual limb circuits. RPT devices typically include a pressure generator (e.g., a powered blower or compressed gas reservoir) and are configured to deliver airflow to the patient's airway. In some cases, the airflow may be delivered at positive pressure to the patient's airway. The outlet of the RPT device is connected via an air circuit to a patient interface as described above.

A device designer may be presented with a myriad of options. Often, design criteria conflict, making certain design choices unconventional or unavoidable. Furthermore, the comfort and effectiveness of a particular implementation may be significantly affected by minor changes in one or more parameters.
2.2.3.3 Humidifier

Airflow delivery without humidification can lead to drying of the airway. When a humidifier is used with the RPT device and patient interface, humidified gas is produced, minimizing drying of the nasal mucosa and increasing comfort of the patient airway. Additionally, in cooler climates, the application of warm air to the facial area surrounding the patient interface generally provides more comfort than cool air.

A range of artificial humidification devices and systems are known, but they do not meet the special requirements of medical humidifiers.

Medical humidifiers are typically used when a patient is sleeping or resting (e.g., in a hospital) to increase the humidity and/or temperature of an air stream relative to the ambient air when necessary. Bedside medical humidifiers may be small. Medical humidifiers may be configured to only humidify and/or heat the air stream delivered to the patient, and not the patient's surroundings. For example, while room-based systems (e.g., saunas, air conditioners, or evaporative coolers) may also humidify the air breathed into the patient's body, these systems also humidify and/or heat the entire room, which may be uncomfortable for occupants. Additionally, medical humidifiers may have more stringent safety constraints than industrial humidifiers.

Although a number of medical humidifiers are known, such medical humidifiers may suffer from one or more deficiencies, such that some provide inadequate humidification or are difficult or inconvenient for the patient to use.
2.2.3.4 Data Management

For clinical reasons, data may be obtained to determine whether a patient prescribed respiratory treatment is "compliant" (e.g., whether the patient follows certain "compliance rules" with their RPT device). One example of a compliance rule for CPAP treatment is that a patient must use the RPT device for at least 4 hours per night for at least 21 days out of 30 consecutive days to be considered compliant. To determine patient compliance, a provider of the RPT device (e.g., a healthcare provider) may manually obtain data describing the patient's treatment with the RPT device, calculate a usage rate over a given period of time, and compare this to the compliance rules. Once the healthcare provider determines that the patient has used their RPT device in accordance with the compliance rules, the healthcare provider may notify a third party that the patient is compliant.

There may be other aspects of a patient's care that would benefit from communication of treatment data to third parties or external systems.

Existing processes for communicating and managing such data can be one or more of: costly, time consuming, and error prone.
2.2.3.5 Repositioning the mandible

The Mandibular Repositioning Device (MRD) or Mandibular Advancement Device (MAD) is one of the treatment options for sleep apnea and snoring. It is an adjustable oral appliance available from dentists or other suppliers that holds the mandible (lower jaw) in an anterior position during sleep. The MRD is a removable device that is inserted into the oral cavity before the patient sleeps and removed afterwards. As such, MRDs are not designed for full-time wear. MRDs may be custom made or manufactured in standard forms and include bite impression sites designed to fit the patient's teeth. This mechanical protrusion from the mandible expands the space behind the tongue and applies tension on the pharyngeal wall to reduce airway collapse and reduce palate vibration.

In certain embodiments, the mandibular advancement device may include an upper splint intended to engage or mate with teeth on the upper jaw or maxilla, and a lower splint intended to engage or mate with teeth on the upper jaw or mandible. The upper and lower splints are laterally connected to each other via a pair of connecting rods that are fixed symmetrically on the upper and lower splints.

In such a design, the length of the connecting rod is selected so that the mandible is held in an anterior position when the MRD is placed in the patient's mouth. The length of the connecting rod can be adjusted to vary the level of protrusion of the mandible. The dentist can determine the level of protrusion to suit the mandible, which in turn determines the length of the connecting rod.

Some MRDs are configured to push the mandible forward relative to the maxilla, while others, such as the ResMed Narval CC® MRD, are designed to hold the mandible in an anterior position. The device also reduces or minimizes dental and temporomandibular joint (TMJ) side effects. As such, the device is configured to minimize or avoid any movement of one or more of the teeth.
2.2.3.6 Ventilation technology

Some forms of treatment systems may include a vent to push out exhaled carbon dioxide. The vent may allow gas flow from an interior space of the patient interface (e.g., a plenum chamber) to an exterior of the patient interface (e.g., the surroundings).

The vent may include an orifice through which gas may flow when the mask is in use. Many such vents are noisy. Others may become blocked when in use, resulting in insufficient pumping. Some vents may disrupt sleep for the patient 1000 and bed companion 1100, for example, due to noise or airflow concentration.

ResMed Limited has developed several improved mask ventilation technologies. See: U.S. Patent No. 5,393, 611; ... and U.S. Patent No. 5,393, 611.

Conventional mask noise table (ISO17510-2:2007, ₁₀ cmH2O pressure at 1m)

(*Only one sample was measured at ₁₀ cmH2O in CPAP mode using the test method specified in ISO3744)

The sound pressure values for various objects are listed below.

2.2.4 Diagnostic and Monitoring Systems Polysomnography (PSG) is a conventional system for diagnosing and monitoring cardiopulmonary diseases, and typically requires specialized clinical staff for system application. In PSG, typically 15-20 contact sensors are placed on the human body to record various body signals (e.g., electroencephalography (EEG), electrocardiography (ECG), electrooculography (EOG), electromyography (EMG)). For PSG of sleep-disordered breathing, the patient needs to be observed for two nights in a specialized hospital; the first night is purely for diagnosis, and the second night is required for titration of treatment parameters by the clinician. Therefore, PSG is expensive and inconvenient. PSG is particularly unsuitable for home sleep testing.
A clinical expert may adequately diagnose or monitor a patient based on visual observation of the PSG signal. However, there are situations where a clinical expert is not available or cannot be paid for. Different clinical experts may have different opinions about a patient's condition. Furthermore, a given clinical expert may apply different criteria at different times.

U.S. Pat. No. 4,944,310 U.S. Patent No. 6,532,959 WO 1998/004,310 WO 2006/074,513 WO 2010/135,785 U.S. Pat. No. 4,782,832 WO 2004/073,778 U.S. Patent Application No. 2009/0044808 WO 2005/063,328 WO 2006/130,903 WO 2009/052,560 US Patent Application Publication No. 2010/0000534 WO 1998/034,665 WO 2000/078,381 U.S. Patent No. 6,581,594 US Patent Application Publication No. 2009/0050156 US Patent Application Publication No. 2009/0044808

"Respiratory Physiology", by John B. West, Lippincott Williams & Wilkins, 9th edition published 2012

3 Brief Description of the Technology The present technology relates to the provision of medical devices for use in the diagnosis, amelioration, treatment or prevention of respiratory disorders, which medical devices have one or more of improved comfort, cost, effectiveness, ease of use and manufacturability.

A first aspect of the present technology relates to an apparatus for use in the diagnosis, amelioration, treatment or prevention of respiratory diseases.

Another aspect of the technology relates to methods for use in the diagnosis, amelioration, treatment or prevention of respiratory disorders.

One aspect of certain forms of the present technology is to provide a method and/or device that improves patient compliance with respiratory treatment.

One aspect of the present technology relates to a humidifier that includes a water reservoir that includes a non-metallic thin film base adapted for thermal engagement with a heating plate. The thin film base of the water reservoir is structured to provide an arrangement that reduces the production costs of the water reservoir while maintaining or improving the heat transfer characteristics and reliability of the water reservoir. In one embodiment, the thin film base can be sufficiently thin and flat to provide good thermal contact and good humidifier performance and allow for appropriate material selection depending on, for example, humidifier requirements and performance.

One aspect of the technology relates to a water reservoir for an apparatus for humidifying a flow of breathable gas. The water reservoir includes a reservoir base including a cavity structured to hold a volume of liquid and a conductive portion disposed in the base. The conductive portion is adapted to thermally engage the heating plate to allow thermal transfer of heat from the heating plate to the volume of liquid. The conductive portion includes a thin film including a non-metallic material, the thin film including a wall thickness of less than about 1 mm.

In one embodiment, the membrane may have a thickness of less than about 0.5 mm. In one embodiment, the membrane may include silicone, polycarbonate, or other thermoplastic or elastomeric material. In one embodiment, the membrane may be provided as a structure separate and distinct from the reservoir base. In one embodiment, the membrane includes a preformed structure that is secured or otherwise secured to the reservoir base. In one embodiment, the reservoir base may include a hole structured to receive the membrane. In one embodiment, the membrane may include a shape corresponding to the shape of the hole. In one embodiment, the membrane may be generally planar. In one embodiment, the membrane may include a first side adapted to form a bottom inner surface of the water reservoir exposed to the volume of liquid, and a second side opposite the first side adapted to form a bottom outer surface of the water reservoir exposed to the heating plate. In one embodiment, the second side of the membrane may provide a contact surface structured and arranged to directly engage the heating plate. In one embodiment, the non-metallic material of the membrane can be similar to the material of the reservoir base. In one embodiment, the thickness of the membrane can be less than the wall thickness of the wall of the reservoir base. In one embodiment, the water reservoir can further include one or more ribs that are constructed and arranged to extend over the membrane to generate a force adapted to press the membrane against the heating plate. In one embodiment, the reservoir base can include a base upper body, a base lower plate, and a membrane. The base upper body, the base lower plate, and the membrane form a cavity. In one embodiment, the water reservoir can further include a reservoir lid. The reservoir lid is movably connected to the reservoir base such that the water reservoir can be converted between an open configuration and a closed configuration.

Another aspect of the present technology relates to a water reservoir for an apparatus for humidifying a flow of breathable gas. The water reservoir includes a reservoir base including a cavity structured to hold a volume of liquid and a conductive region disposed to the base. The conductive region is adapted to thermally engage a heating plate to allow thermal transfer of heat from the heating plate to the volume of liquid. The conductive region includes a membrane including a non-metallic material. The membrane is provided as a structure separate and distinct from the reservoir base, the membrane including a wall thickness less than a wall thickness of the wall of the reservoir base. In one embodiment, the membrane may include a preformed structure that is secured or otherwise secured to the reservoir base.

One aspect of the present technology is a method for manufacturing a device.

One aspect of certain forms of the present technology is a medical device that is easy to use, for example, by individuals without medical training, individuals with limited dexterity or insight, or individuals with limited experience using such medical devices.

One aspect of this technology is a patient interface that can be cleaned in the patient's home, for example with soapy water, without the need for special cleaning equipment. One aspect of this technology is a humidifier tank that can be cleaned in the patient's home, for example with soapy water, without the need for special cleaning equipment.

The methods, systems, devices, and apparatus described herein may enable improved functionality in a processor (e.g., a processor of a special purpose computer, a respiratory monitor, and/or a respiratory treatment device). Additionally, the described methods, systems, devices, and apparatus enable advances in the art of automated management, monitoring, and/or treatment of respiratory conditions (e.g., sleep disordered breathing).

Of course, some of the above aspects may form sub-aspects of the present technology. Also, various combinations of the sub-aspects and/or aspects may form further aspects or sub-aspects of the present technology.

Other features of the present technology will become apparent in light of the information contained in the following detailed description, abstract, drawings and claims.

4. BRIEF DESCRIPTION OF THE DRAWINGS The present technology is illustrated by way of non-limiting example in the accompanying drawings, in which like reference characters include like elements:
4.1 Treatment system
1A shows a system including a patient 1000 wearing a patient interface 3000. The system takes the form of nasal pillows and receives air at positive pressure supplied by an RPT device 4000. The air from the RPT device 4000 is humidified by a humidifier 5000 and travels along an air circuit 4170 to the patient 1000. A bed companion 1100 is also shown. The patient is sleeping in a supine sleep position. 1B shows a system including a patient 1000 wearing a patient interface 3000, which takes the form of a nasal mask, receiving air at positive pressure supplied by an RPT device 4000. The air from the RPT device is humidified by a humidifier 5000 and travels along an air circuit 4170 to the patient 1000. 1C shows a system including a patient 1000 wearing a patient interface 3000. The patient interface 3000 takes the form of a full face mask and receives a positive pressure air supply from an RPT device 4000. Air from the RPT device is humidified by a humidifier 5000 and travels along an air circuit 4170 to the patient 1000. The patient is sleeping in a lateral sleep position. 4.2 Respiratory System and Facial Anatomy FIG. 2A shows an overview of the human respiratory system, including the nasal and oral cavities, larynx, vocal cords, esophagus, trachea, bronchi, lungs, alveolar sacs, heart and diaphragm. 2B is a diagram of the human upper airway including the nasal cavity, nasal bones, lateral nasal cartilages, greater alar cartilage, nostrils, upper lip, lower lip, larynx, hard palate, soft palate, oropharynx, tongue, epiglottis, vocal cords, esophagus, and trachea. 4.3 Patient Interface FIG. 3A shows a patient interface in the form of a nasal mask in accordance with one form of the present technology. 3B is a schematic cross-sectional view of the structure cut at a point, where the outward normal is shown, and the curvature at this point has a positive sign and a relatively large magnitude compared to the magnitude of curvature shown in 3C. Figure 3C is a schematic cross-sectional view of the structure cut at a point, where the outward normal is shown, and the curvature at this point has a positive sign and a relatively small magnitude compared to the magnitude of curvature shown in Figure 3B. 3D is a schematic cross-sectional view of the structure cut at a point, where the outward normal is illustrated, and where the curvature value is zero. Figure 3E is a schematic cross-sectional view of the structure cut at a point, where the outward normal is shown, and the curvature at this point has a negative sign and a relatively small magnitude compared to the magnitude of curvature shown in Figure 3F. Figure 3F is a schematic cross-sectional view of the structure cut at a point, where the outward normal is shown, and the curvature at this point has a negative sign and a relatively large magnitude compared to the magnitude of curvature shown in Figure 3E. 3G shows a mask cushion including two pillows. The outer surface of the cushion is shown. The edge of the surface is shown. The dome region and the saddle region are shown. 3H shows a cushion for a mask. The outer surface of the cushion is illustrated. The edge of the surface is illustrated. The path on the surface between points A and B is illustrated. The straight line distance between A and B is illustrated. Two saddle regions and a dome region are illustrated. 3I shows the surface of a structure with a one-dimensional hole drilled into it. The planar curves shown form the boundary of the one-dimensional hole. Figure 3J is a cross-sectional view through the structure of Figure 31. The surfaces shown bound a two-dimensional hole in the structure of Figure 3I. Figure 3K is a perspective view of the structure of Figure 3I including a two-dimensional hole and a one-dimensional hole, and also illustrates the surfaces bounding the two-dimensional hole in the structure of Figure 3I. FIG. 3L shows a mask with an inflatable bladder as a cushion. Figure 3M is a cross-sectional view of the mask of Figure 3L showing the inner surface of the bladder, which bounds the two-dimensional hole in the mask. Figure 3N shows a further cross section through the mask of Figure 3L. The inner surface is also shown. FIG. 3O illustrates the left-hand rule. FIG. 3P illustrates the right-hand rule. FIG. 3Q shows the left ear including the left ear helix. FIG. 3R shows the right ear including the right ear helix. FIG. 3S shows a right-handed spiral. FIG. 3T is a diagram of a mask including the sign of the twist of the space curve defined by the edges of the sealing membrane in different regions of the mask. 4.4 RPT Device 4A shows an RPT device 4000 in accordance with one form of the present technology. FIG. 5 is a perspective view of an RPT device and integrated humidifier according to an embodiment of the present technology, illustrating the engagement of the humidifier with an air circuit according to an embodiment of the present technology. FIG. 6 is a perspective view of the RPT device and integrated humidifier of FIG. 5 illustrating engagement of the humidifier reservoir with a reservoir dock according to one embodiment of the present technology. 7 is another perspective view of the RPT device and integrated humidifier of FIG. 5. FIG. 8 is another perspective view of the RPT device and integrated humidifier of FIG. 5 illustrating engagement of the humidifier reservoir with a reservoir dock according to one embodiment of the present technology. FIG. 9 illustrates various views of a humidifier reservoir in accordance with one embodiment of the present technology, with FIG. 9 showing the humidifier reservoir in a closed configuration. FIG. 10 illustrates various views of a humidifier reservoir in accordance with one embodiment of the present technology, with FIG. 10 showing the humidifier reservoir in a closed configuration. FIG. 11 illustrates various views of a humidifier reservoir in accordance with one embodiment of the present technology, with FIG. 11 showing the humidifier reservoir in a closed configuration. FIG. 12 illustrates various views of a humidifier reservoir in accordance with one embodiment of the present technology, with FIG. 12 showing the humidifier reservoir in an open configuration. FIG. 13 is a top perspective view of a reservoir base of a humidifier reservoir according to an embodiment of the present technology. 14 is a bottom perspective view of the reservoir base of FIG. 13. FIG. FIG. 15 is an exploded view of the reservoir base of FIG. FIG. 16 is a cross-sectional view of a humidifier reservoir including the reservoir base of FIG. 13 in accordance with an embodiment of the present technology. 17 is a cross-sectional view of the base bottom plate and conductive region of the reservoir base of FIG. 13 in accordance with an embodiment of the present technology. FIG. 18 is a top perspective view of a reservoir base of a humidifier reservoir in accordance with another embodiment of the present technology. 19 is a bottom perspective view of the reservoir base of FIG. 18. FIG. 20 is a cross-sectional view of the base bottom plate and conductive region of the reservoir base of FIG. 18 in accordance with an embodiment of the present technology. FIG. 21 is a schematic diagram of a humidifier in accordance with one form of the present technology.

5 Detailed Description of the Examples of the Technology Before describing the technology in more detail, it should be understood that the technology is not limited to the specific examples described herein, which may vary. It should also be understood that the terms used in the present disclosure are for the purpose of describing the specific examples described herein, and are not limiting.

The following description is provided in conjunction with various embodiments that may share one or more common characteristics and/or features. It should be understood that one or more features of any one embodiment may be combined with one or more features of another or other embodiment. In addition, any single feature or combination of features in any of these embodiments may constitute an additional embodiment.
5.1 Treatment

In one form, the technology includes a method for treating a respiratory disorder. The method includes applying positive pressure to an entrance of an airway of a patient 1000.

In certain embodiments of the present technology, a supply of air at positive pressure is provided to the patient's nasal passages via one or both nostrils.

In certain embodiments of the present technology, mouth breathing is restricted, limited or prevented.
5.2 Treatment system

In one form, the present technology includes an apparatus or device for the treatment of respiratory disorders. The apparatus or device may include an RPT device 4000 that supplies pressurized air to a patient 1000 via an air circuit 4170 to a patient interface 3000 (see, for example, FIGS. 1A-1C).
5.3 Patient Interface

As shown in FIG. 3A, a non-invasive patient interface 3000 according to one aspect of the present technology includes the following functional aspects: a seal-forming structure 3100, a plenum chamber 3200, a positioning and stabilizing structure 3300, a vent 3400, a form of connection port 3600 for connection to an air circuit 4170, and a forehead support 3700. In some forms, the functional aspects may be provided by one or more physical components. In some forms, a single physical component may provide one or more functional aspects. In use, the seal-forming structure 3100 is positioned to surround the entrance of the patient's airway to facilitate the supply of air at positive pressure to the airway.

If the patient interface cannot comfortably deliver a minimum level of positive pressure to the airway, the patient interface may be unsuitable for respiratory pressure therapy.

A patient interface 3000 in accordance with one form of the present technology is constructed and arranged to provide an air supply at a positive pressure of at least 6 _cmH2O relative to ambient.

A patient interface 3000 in accordance with one form of the present technology is constructed and arranged to provide an air supply at a positive pressure of at least 10 _cmH2O relative to ambient.

A patient interface 3000 in accordance with one form of the present technology is constructed and arranged to provide an air supply at a positive pressure of at least 20 _cmH2O relative to ambient.
5.4 RPT Device

An RPT device 4000 according to one aspect of the present technology includes mechanical, pneumatic, and/or electrical components and is configured to execute one or more algorithms (see FIG. 4A). The RPT device 4000 may be configured to generate an airflow that is delivered to a patient's airway for treatment of one or more of the respiratory conditions described anywhere herein, for example.

In one form, the RPT device 4000 is constructed and arranged to deliver air flows in the range of -20 L/min to +150 L/min while maintaining a positive pressure of at least ₆ cmH2O, or at least ₁₀ cmH2O, or at least ₂₀ cmH2O.

The power source may be located inside or outside the external housing of the RPT device 4000.

In one form of the present technology, the power source provides power only to the RPT device. In another form of the present technology, power is provided from the power source to both the RPT device 4000 and the humidifier 5000.

In one form of the present technology, the RPT device 4000 includes a central controller including one or more processors suitable for controlling the RPT device 4000.

Suitable processors may include x86 INTEL processors, processors based on the ARM® Cortex®-M processor from ARM Holdings (e.g., the S®32 series of microcontrollers from ST Microelectronics). In certain alternative forms of the present technology, 32-bit RISC CPUs (e.g., the STR9 series of microcontrollers from ST Microelectronics) or 16-bit RISC CPUs (e.g., processors from the MSP430 family of microcontrollers manufactured by TEXAS INSTRUMENTS) may also be suitable.

In one form of the technology, the central controller is a dedicated electronic circuit.

In one form, the central controller is an application specific integrated circuit. In another form, the central controller includes discrete electronic components.

The central controller may be configured to receive input signal(s) from one or more transducers, one or more input devices, and the humidifier 5000.

The central controller may be configured to provide output signal(s) to one or more of the output device, the treatment device controller, the data communication interface, and the humidifier 5000.

In some forms of the present technology, a central controller is configured to implement one or more of the methods described herein (e.g., one or more algorithms expressed as a computer program stored in a non-transitory computer readable recording medium (e.g., memory)). In some forms of the present technology, the central controller may be integrated with the RPT device 4000. However, in some forms of the present technology, some of the methods may be performed by a remotely located device. For example, the remotely located device may determine ventilator control settings or detect respiratory related events by analysis of recorded data (e.g., from any of the sensors described herein).
5.5 Air Circuit

The air circuit 4170 according to one aspect of the present technology is a conduit or tube constructed and arranged to move air flow between two components (e.g., the RPT device 4000 and the patient interface 3000) when in use.

In particular, the air circuit 4170 may be fluidly connected to the outlet of the pneumatic block and the patient interface. The air circuit may be referred to as an air delivery tube. In some cases, there may be separate limbs of the circuit for inhalation and exhalation. In other cases, a single limb is used.

In some forms, the air circuit 4170 may include one or more heating elements configured to heat the air in the air circuit (e.g., to maintain or increase the air temperature). The heating elements may take the form of a heated wire circuit and may include one or more transducers (e.g., temperature sensors). In one form, the heated wire circuit may be spirally wound around the axis of the air circuit 4170. The heating elements may be in communication with a controller (e.g., a central controller). One example of an air circuit 4170 including a heated wire circuit is described in U.S. Patent Application No. 8,733,349, which is incorporated by reference in its entirety.
5.6 Humidifier 5.6.1 Overview of the humidifier

In one form of the present technology, a humidifier is provided for changing the absolute humidity of air or gas to be delivered to a patient relative to the ambient air. Typically, a humidifier is used to increase the absolute humidity (relative to ambient air) and increase the temperature of the air stream before delivery to the patient's airway.

FIGS. 5-8 show an RPT device 4000 and an integrated humidifier 5000 according to one embodiment of the present technology. In the illustrated example, the humidifier 5000 includes a water reservoir dock 5130 structured to receive a water reservoir 5110. As shown, the water reservoir dock 5130 includes a cavity 5160 formed to receive the water reservoir 5110 therein. For example, the water reservoir 5110 may be insertable/removable from the water reservoir dock 5110 in a lateral direction.

In the illustrated example, the RPT device 4000 is integrated with the humidifier 5000. In this arrangement, the water reservoir dock 5130 is structured to connect the water reservoir 5110 to the air pressure path. As best shown in FIGS. 5 and 8, the reservoir dock 5130 includes a dock air outlet 5168 for delivering an air flow to the water reservoir 5110, a dock air inlet 5170 for receiving the humidified air flow at the water reservoir 5110, and a humidifier outlet 5172 for transferring the humidified air flow to the air circuit 4170. The cavity 5160 may include an upper portion configured to cover at least a portion of the lid of the water reservoir 5110 and a lower portion including a heating plate 5120.

However, it should be understood that in an alternative arrangement, the reservoir dock 5130 may be provided separately to the RPT device 4000. In such an arrangement, an additional interface may be used to connect the reservoir dock 5130 to the RPT device 4000 (e.g., for direct coupling or coupling via an air circuit).

In another arrangement, the water reservoir dock 5130 may include an opening in a substantially horizontal plane so that the water reservoir 5110 can be inserted from the top or bottom of the water reservoir dock 5130.

Further examples and details of such an RPT device 4000 and integrated humidifier 5000 are described in WO 2014/138804, filed September 18, 2014, the entirety of which is incorporated herein by reference.
5.6.2 Humidifier Components 5.6.2.1 Water Reservoir

9-12 show one form of the water reservoir or tub 5110. The water reservoir or tub 5110 includes a reservoir base 5112, a reservoir lid 5114, and a middle section including a compliant section 5116. The water reservoir 5110 may include a cavity (e.g., provided by the base) configured to contain or hold a quantity of liquid (e.g., water) to be evaporated for humidification of the airflow. The water reservoir 5110 may be configured to contain a predetermined maximum quantity of water to provide adequate humidification for at least the duration of a respiratory therapy session (e.g., a night's sleep). Typically, the reservoir 5110 is configured to contain several hundred milliliters of water (e.g., 300 milliliters (ml), 325 ml, 350 ml, or 400 ml). In other forms, the humidifier 5000 may be configured to receive a water supply from an external water source (e.g., a building's water supply system).

According to one aspect, the water reservoir 5110 is configured to humidify the air flow from the RPT device 4000 as the air flow passes through the RPT device 4000. In one form, the water reservoir 5110 may be configured to promote the air flow to travel a tortuous path through the reservoir 5110 while the air flow contacts a volume of water in the reservoir 5110.

The reservoir 5110 may also be configured to inhibit liquid release from the reservoir 5110, for example, when the reservoir 5110 is displaced and/or rotated from its normal operating orientation (e.g., through any aperture and/or between its subcomponents). Because the air flow to be humidified by the humidifier 5000 is often pressurized, the reservoir 5110 may also be configured to prevent loss of air pressure through leakage and/or flow impedance.

In the illustrated example, the reservoir lid 5114 includes an inlet 5118 for receiving airflow into the reservoir 5110 and an outlet 5122 for delivery of airflow from the reservoir 5110. The reservoir lid 5114 is pivotally connected to the base 5112 by a hinge 5158 such that the reservoir 5110 can be converted between a closed configuration as shown in FIGS. 9-11 and an open configuration as shown in FIG. 12. When the water reservoir 5110 is in its closed configuration, the compliant portion 5116 is sealingly engaged between the base 5112 and the lid 5114, thereby sealing the base 5112 and the lid 5114 and preventing water leakage from the reservoir 5110. The compliant portion 5116 may also perform other functions, such as improving thermal contact between the reservoir 5110 and the heating plate 5120.

The reservoir base 5112 may be configured as a container that holds a given maximum volume of liquid that the reservoir 5110 is configured to hold. In one form, the base 5112 may include additional features, such as an overfill prevention feature. (e.g., at least one orifice 5138 in the water reservoir 5110 to indicate overfill as shown in FIG. 13)

In one form, the reservoir base 5112 may further include an inner lip 5224 and/or an outer lip 5226, as shown, for example, in FIG. 13. According to one aspect, the inner lip 5224 and/or the outer lip 5226 may prevent liquid from leaking from the reservoir 5110 through an interface between the middle portion (e.g., the compliant portion 5116) and the base 5112 (e.g., when the middle portion is compressed or under vibration).

In one form, the reservoir base 5112 includes a base upper body 5146, a base lower plate 5148, and a conductive portion 5152. The base upper body 5146 is formed with the base lower plate 5148 and the conductive portion 5152 to form a container (see, for example, FIG. 15). However, it should be understood that the reservoir base 5112 may be constructed of any number of components.

In one embodiment, the base upper body 5146, the base lower plate 5148 and/or the lid 5114 may be constructed from a biocompatible material suitable for holding a volume of liquid, such as a plastic or thermoplastic polymer (e.g., acrylonitrile butadiene styrene (ABS) or a polycarbonate material).

In one embodiment, a sealing element can be provided, for example between the base upper body 5146 and the base lower plate 5148, to prevent water leakage from the water reservoir 5110 (particularly from the base 5112).

Further examples and details of the water reservoir are described in WO 2014/138804, filed September 18, 2014, which is hereby incorporated by reference in its entirety.
5.6.2.2 Conductive sites

According to one embodiment of the present technology, the reservoir 5110 includes a conductive portion 5152 configured to enable efficient heat transfer from the heating plate 5120 to the volume of liquid in the reservoir 5110. The conductive portion 5152 includes a thermally conductive material constructed and arranged to be in thermal engagement or contact with the heating plate 5152 to enable thermal transfer of heat from the heating plate to the volume of liquid.

In the illustrated example of Figures 13-20, the conductive portion 5152 includes a thin film (also called a film base or base conductor film) that includes a thermally conductive non-metallic material configured to be thermally coupled to the heating plate 5120 of the humidifier 5000.

In one embodiment, the thermally conductive non-metallic material of the thin film 5152 may include silicone, polycarbonate or other thermoplastic or elastomeric material.

In one embodiment, the membrane 5152 may have a thickness of about 0.05 mm to 1.5 mm (e.g., 0.10 mm to 0.125 mm). In one embodiment, the membrane may have a thickness of less than about 1 mm (e.g., less than about 0.5 mm). In one form, the membrane may include a silicone (LSR) membrane having a thickness of about 0.4 mm.

In the illustrated example, the base lower plate 5148 includes a side wall 5149.1 extending around the periphery of the base lower plate and a bottom wall 5149.2 joining the side wall 5149.1 (see, e.g., FIG. 17). A membrane 5152 is provided or otherwise provided into the bottom wall 5149.2 to form a container for holding liquid. In the illustrated example, the bottom wall 5149.2 includes a hole 5149.3 configured to receive the membrane 5152 (see, e.g., FIG. 15). The membrane 5152 is sealingly secured within and/or across the hole 5149.3 in the operative position to form at least a portion of the base of the container and prevent water leakage from the water reservoir 5110.

For example, the membrane 5152 may include a shape that corresponds to the shape of the hole 5149.3 such that the inner surface that forms the edge of the hole 5149.3 is secured to the edge at the periphery of the membrane 5152. Alternatively, the membrane 5152 may include a shape that is different from the shape of the hole 5149.3, in which case the edge at the periphery of the membrane 5152 extends beyond the edge of the hole 5149.3 (e.g., the membrane 5152 overlaps the lower wall 5149.2 of the base lower plate 5148). In the illustrated example, the membrane 5152 includes a shape that generally corresponds to the shape of the heating plate 5120 (e.g., rectangular), although other suitable shapes are possible (e.g., square, circular, elliptical).

As shown, the membrane 5152 includes a first side 5152.1 adapted to form a bottom inner surface of the reservoir 5110 exposed to the water. The membrane 5152 includes a second side 5152.2 opposite the first side 5152.1. The second side 5152.2 is adapted to form a bottom outer surface of the reservoir 5110 exposed to the heating plate 5120. For example, the second side 5152.2 of the membrane 5152 provides a contact surface that is constructed and arranged to directly engage the heating plate 5120.

In the illustrated example, the membrane 5152 is generally planar and disposed on the bottom of the reservoir. However, the membrane 5152 may include non-planar shapes and may be disposed on other areas of the reservoir (e.g., along the sidewalls of the reservoir exposed to the water). In one embodiment, the membrane 5152 may overlap one or more walls of the base underplate 5148 (e.g., a membrane that extends across a hole in the base underplate and is shaped to conform and overlap the bottom and/or sidewalls of the base underplate 5148).

In one embodiment, the membrane 5152 is provided as a separate and distinct structure from the base plate 5148 and is secured or otherwise secured to the base plate 5148 in the operative position (e.g., the membrane 5152 comprises a preformed structure secured to the base plate 5148).

In one example, the membrane 5152 may be preformed and then insert molded into the base underplate 5148. In another example, the membrane 5152 may be preformed and then secured (e.g., by adhesive or welding) to the base underplate 5148. In yet another example, the membrane 5152 may be provided to the base underplate 5148 by overmolding the membrane 5152 onto the base underplate 5148.

In one embodiment, the base plate 5148 may be eliminated or the membrane may be otherwise supported or reinforced (e.g., at least one reinforcing strip of a stiffer material than the membrane may be embedded or otherwise provided in the membrane). In one embodiment, the membrane may be provided to the base body 5146 such that the membrane constitutes the entire lower portion of the reservoir.

In an arrangement in which a preformed membrane 5152 is provided (e.g., insert molded or bonded) to the base underplate 5148, the membrane may comprise a thermoplastic polycarbonate membrane material (e.g., Makrofol DE1-4 material having a thickness of about 0.1 mm) and the base underplate 5148 may comprise a thermoplastic polycarbonate material (e.g., Makrolon 2458 (or Makrolon 2258) material). However, it should be understood that the preformed membrane and/or the base underplate may comprise other suitable materials.

In one embodiment, the membrane may be filled with one or more additives to improve thermal conductivity, in which case the membrane may be thicker (e.g., for improved mechanical stability).

For example, the membrane may include plastic filled with ceramic or metal powder, or the membrane may include multiple membranes or layers (e.g., a sandwich structure including a metal membrane with a plastic membrane on one or both sides of the metal membrane).

In one embodiment, improved thermal conductivity can be achieved by applying a powder coating or spray painting of a thermally conductive material (e.g., metal) to the second side 5152.2 of the membrane facing the heating plate 5120.

In one embodiment, the membrane 5152 can include a thickness that is different than the thickness of the bottom wall and/or side wall of the base plate 5148. For example, the wall thickness of the membrane is less than the wall thickness of the bottom wall and/or side wall of the base plate 5148. Such an arrangement allows the membrane thickness to be appropriately selected to achieve desired performance characteristics (e.g., performance at high flow rates, humidification rate, heat up time).

In one embodiment, the membrane 5152 can include a material similar to the material of the base upper body 5146 and/or the base lower plate, and the membrane 5152 includes a wall thickness that is less than the wall thickness of the walls of the base upper body 5146 and/or the base lower plate 5148.

In one embodiment, as shown in Figures 18-20, the reservoir 5110 may be provided with one or more ribs 5175 that are constructed and arranged to extend over the membrane 5152 to generate a force adapted to press the membrane 5152 against the heating plate 5120.

Alternatively or additionally, the humidifier may be provided with a spring-like element constructed and arranged to press the heating plate 5120 against the membrane 5152.

The thin film base 5152 of the reservoir provides an arrangement that reduces reservoir production costs while maintaining or improving reservoir heat transfer characteristics and reliability. For example, a thin film base is advantageous in that it can be made thin and flat enough to provide good thermal contact and good humidifier performance and to allow for, for example, selection of appropriate materials depending on humidifier requirements and performance.

In one embodiment, the thin film base may be advantageous because the non-metallic properties (e.g., thermoplastic or elastomeric material properties) of the thin film base provide corrosion protection (e.g., water resistance) and a sealed connection with the base lower plate 5148 (e.g., to form a sealed reservoir for humidification water). The non-metallic properties (e.g., thermoplastic or elastomeric material properties) of the thin film base may also facilitate the manufacture of the thin film base to have complex shapes. For example, the thin film base can be molded into complex shapes to meet the design requirements of the humidifier when necessary. Furthermore, reducing the production cost of the reservoir is particularly desirable when the reservoir is disposable. In such cases, the reservoir is intended to be used only for a certain product life, and the reservoir is replaced periodically by the hospital, the patient, or the user.
5.6.2.3 Humidifier Reservoir Dock

As mentioned above, the humidifier 5000 may include a humidifier reservoir dock 5130 (as shown in FIGS. 5-8 ) configured to receive the humidifier reservoir 5110. In some arrangements, the humidifier reservoir dock 5130 may include a locking feature configured to retain the reservoir 5110 within the humidifier reservoir dock 5130.
5.6.2.4 Water level indicator

The humidifier reservoir 5110 may include a water level indicator. In some forms, the water level indicator may provide one or more indications to a user, such as the patient 1000 or a caregiver, about the amount of water in the humidifier reservoir 5110. The one or more indications provided by the water level indicator may include an indication of a maximum predetermined amount of water, any fraction thereof (e.g., 25%, 50%, or 75% or an amount (e.g., 200 ml, 300 ml, or 400 ml)).
5.6.2.5 Humidifier transducer(s)

As shown in FIG. 21, the humidifier 5000 may include one or more humidifier transducers (sensors) 5210 instead of or in addition to the transducers provided in the RPT device 4000. The humidifier transducers 5210 may include one or more of an air pressure sensor 5212, an air flow transducer 5214, a temperature sensor 5216, or a humidity sensor 5218 as shown in FIG. The humidifier transducers 5210 may generate one or more output signals. These output signals may be communicated to a controller (e.g., a central controller of the RPT device 4000 and/or a central humidifier controller 5250). In some forms, the humidifier transducers may be located outside the humidifier 5000 (e.g., within the air circuit 4170) while communicating the output signals to the controller.
5.6.2.5.1 Pressure transducer

One or more pressure transducers 5212 may be provided to the humidifier 5000 in addition to or in place of a pressure sensor provided in the RPT device 4000.
5.6.2.5.2 Flow converter

In addition to or in lieu of a flow sensor provided in the RPT device 4000, one or more flow transducers 5214 may be provided to the humidifier 5000.
5.6.2.5.3 Temperature converter

The humidifier 5000 may include one or more temperature transducers 5216. The one or more temperature transducers 5216 may be configured to measure one or more temperatures, such as the temperature of the heating element 5240 and/or the temperature of the air stream downstream of the humidifier outlet. In some forms, the humidifier 5000 may further include a temperature sensor 5216 that detects the temperature of the ambient air.
5.6.2.5.4 Humidity converter

In one form, the humidifier 5000 may include one or more humidity sensors 5218 that detect the humidity of a gas, such as ambient air. In some forms, the humidity sensor 5218 may be positioned toward the humidifier outlet to measure the humidity of the gas delivered from the humidifier 5000. The humidity sensor may be an absolute humidity sensor or may be a relative humidity sensor.
5.6.2.6 Heating elements

In some cases, a heating element 5240 may be provided to the humidifier 5000 to provide heat input to one or more of the volume of water in the humidifier reservoir 5110 and/or the volume of water to the air stream. The heating element 5240 may include a heat generating component such as an electrical resistive heating track. One suitable example of a heating element 5240 is a layered heating element, such as that described in PCT Patent Application WO 2012/171072, the entirety of which is incorporated herein by reference.

In some forms, the heating element 5240 may be mounted in the humidifier base 5006 where heat may be transferred to the humidifier reservoir 5110 primarily by conduction.
5.6.2.7 Humidifier Controller

According to one arrangement of the present technology, the humidifier 5000 may include a humidifier controller 5250 as shown in FIG. 21. In one form, the humidifier controller 5250 may be part of a central controller of the RPT device 4000. In another form, the humidifier controller 5250 may be a separate controller that may communicate with the central controller.

In one form, the humidifier controller 5250 may receive measurements of properties (e.g., temperature, humidity, pressure, and/or flow) as inputs (e.g., measurements of airflow, water in the reservoir 5110 and/or in the humidifier 5000). The humidifier controller 5250 may also be configured to execute or implement a humidifier algorithm and/or deliver one or more output signals.

As shown in FIG. 21, the humidifier controller 5250 may include one or more controllers (e.g., a central humidifier controller 5251, a heated air circuit controller 5254 configured to control the temperature of the heated air circuit 4171, and/or a heating element controller 5252 configured to control the temperature of the heating element 5240).
5.7 Glossary

For purposes of this disclosure, in certain aspects of the technology, one or more of the following definitions may apply. In other aspects of the technology, other definitions may apply.
5.7.1 General

Air: In certain forms of the present technology, air may refer to atmospheric air, while in other forms of the present technology, air may refer to combinations of other breathable gases (e.g., oxygen-rich atmospheric air).

Atmosphere: In certain forms of the present technology, the term "atmosphere" should be taken to mean (i) that which is external to the treatment system or patient, and (ii) that which immediately surrounds the treatment system or patient.

For example, the ambient humidity for a humidifier may be the humidity of the air immediately surrounding the humidifier (e.g., the humidity inside the room in which the patient sleeps). Such ambient humidity may differ from the humidity outside the room in which the patient sleeps.

In another embodiment, the ambient pressure may be the pressure immediately surrounding or external to the body.

In certain embodiments, ambient (e.g., acoustic) noise can be considered the background noise level in the room in which the patient resides, other than noise emanating from, for example, the RPT device or from the mask or patient interface. Ambient noise can originate from sources outside the room.

Automatic Positive Airway Pressure (APAP) Therapy: CPAP therapy that can automatically adjust therapeutic pressure between minimum and maximum limits, for example, between breaths, depending on the presence or absence of symptoms of an SDB episode.

Continuous Positive Airway Pressure (CPAP) Therapy: Respiratory pressure therapy in which the therapeutic pressure is approximately constant throughout the patient's respiratory cycle. In some forms, the pressure at the entrance to the airway increases slightly during expiration and decreases slightly during inspiration. In some forms, the pressure varies during different respiratory cycles of the patient (e.g., increased in response to detection of an indication of partial upper airway obstruction and decreased in the absence of notification of partial upper airway obstruction).

Flow rate: The instantaneous amount (or mass) of air delivered per unit time. Flow rate may refer to an instantaneous quantity. In some cases, references to flow rate refer to a scalar quantity (i.e., a quantity that has only magnitude). In other cases, references to flow rate refer to a vector quantity (i.e., a quantity that has both magnitude and direction). Flow rate may be given the symbol Q. "Flow rate" may also be called "flow" or "airflow" for short.

In the patient breathing example, the flow rate may be nominally positive for the inhalation portion of the patient's breathing cycle, and therefore negative for the exhalation portion of the patient's breathing cycle. Total flow rate Qt is the flow rate of air exiting the RPT device. Ventilator flow rate Qv is the flow rate of air exiting the vent to allow for the outflow of exhaled gases. Leakage flow rate Ql is the flow rate of leakage from the patient interface system or elsewhere. Respiratory flow rate Qr is the flow rate of air received into the patient's respiratory system.

Humidifier: The word "humidifier" is interpreted as meaning a humidification device constructed, arranged or configured with a physical structure capable of providing a therapeutically beneficial amount of water ( _H2O ) vapor to an air stream to improve the medical respiratory condition of a patient.

Leakage: The term "leakage" is taken as an unintended airflow. In one example, leakage may occur due to an imperfect seal between the mask and the patient's face. In another example, leakage may occur at the swivel elbow to the perimeter.

Noise Conduction (Acoustic): In this document, conducted noise refers to noise that is carried to the patient by the pneumatic pathway (e.g., the air circuit and the patient interface and the air therein). In one form, conducted noise can be quantified by measuring the sound pressure level at the end of the air circuit.

Noise Emission (Acoustic): In this document, radiated noise refers to noise carried by the surrounding air to the patient. In one form, radiated noise can be quantified by measuring the sound power/pressure levels of the target in accordance with ISO 3744.

Ventilation noise (acoustic): In this document, ventilation noise refers to the noise generated by airflow through any ventilation (e.g., ventilation holes in the patient interface).

Patient: A person who may or may not have a respiratory disease.

Pressure: Force per unit area. Pressure can be expressed and measured in various units (e.g., _cmH2O , g-f/ ^cm2 , and hectopascals). _{1 cmH2O} is equal to 1 g-f/ ^cm2 , approximately 0.98 hectopascals. In this specification, pressure is given in units of _cmH2O unless otherwise specified.

The pressure in the patient interface is given the symbol Pm, and the therapeutic pressure, which represents the target value that the mask pressure Pm should achieve at this moment, is given the symbol Pt.

Respiratory Pressure Therapy (RPT): The application of an air supply at therapeutic pressure, typically positive relative to the atmosphere, to the airway inlet.

Ventilator: A mechanical device that provides pressure support to a patient during some or all of the work of breathing.
5.7.1.1 Materials

Silicone or silicone elastomer: Synthetic rubber. In this specification, reference to silicone refers to liquid silicone rubber (LSR) or compression molded silicone rubber (CMSR). One commercially available form of LSR is SILASTIC (in a family of products sold under this trademark) manufactured by Dow Corning. Another LSR manufacturer is Wacker. Unless otherwise stated to the contrary, exemplary forms of LSR have a Shore A (or Type A) indentation hardness of about 35 to about 45 as measured by ASTM D2240.

Polycarbonate: A thermoplastic polymer of bisphenol A carbonate.
5.7.1.2 Mechanical properties

Elasticity: The ability of a material to absorb energy during elastic deformation and to release the energy when unloaded.

Elastic: Releases substantially all of the energy upon unloading. Examples include certain silicone and thermoplastic elastomers.

Hardness: The ability of a material to resist deformation of itself (as described, for example, by Young's Modulus or the indentation hardness scale measured over a standardized sample size).
"Soft" materials may include silicone or thermoplastic elastomers (TPEs), and may deform easily, for example under finger pressure.
"Hard" materials may include polycarbonate, polypropylene, steel or aluminum, and do not easily deform under finger pressure, for example.

Stiffness (or rigidity) of a structure or component: The ability of a structure or component to resist deformation when subjected to a load. The load can be a force or a moment (e.g., compression, extension, bending or torsion). A structure or component may offer different resistance in different directions.

Floppy structure or component: A structure or component that changes shape (e.g., bends) within a relatively short period of time (e.g., one second) when forced to support its own weight.

Rigid structure or component: a structure or component that does not substantially change shape when subjected to loads typically encountered in use. An example of such an application may be setting up and maintaining a patient interface in a sealed manner against a patient airway entrance under a pressure load of, for example, approximately 20-30 cm _H2O .

As one example, an I-beam may include a different bending stiffness (resistance to bending load) in a first direction compared to a second, orthogonal direction, hi another example, a structure or component may be floppy in a first direction and stiff in a second direction.
5.7.2 Patient Interface

Anti-Asphyxiation Valve (AAV): A component or subassembly of a mask system that reduces the risk of excessive _CO2 rebreathing by the patient by venting to atmosphere in a fail-safe manner.

Elbow: An elbow is an example of a structure that directs the axis of airflow moving therethrough to change direction through an angle. In one form, the angle may be approximately 90 degrees. In another form, the angle may be greater than or less than 90 degrees. The elbow may have a generally circular cross section. In another form, the elbow may have an oval or rectangular cross section. In certain forms, the elbow may be rotatable, for example, approximately 360 degrees, relative to the mating component. In certain forms, the elbow may be removable from the mating component, for example, via a snap connection. In certain forms, the elbow may be assembled to the mating component via a one-time snap at the time of manufacture, but cannot be removed by the patient.

Frame: Frame is taken to mean a mask structure that supports a tensile load between two or more points that connect the headgear. A mask frame may be a non-airtight load-bearing structure in the mask. However, some forms of mask frames may be airtight.

Headgear: Headgear is taken to mean a form of positioning and stabilizing structure designed for use on the head. For example, the headgear may include a collection of one or more posts, ties, and stiffeners configured to position and hold the patient interface in place on the patient's face for delivery of respiratory therapy. Some ties are formed from a soft, flexible, elastic material (e.g., a layered composite of foam and fabric).

Membrane: A membrane is taken to mean an element that is typically thin-walled and preferably offers substantially no resistance to bending and resistance to stretching.

Plenum chamber: A mask plenum chamber is taken to mean a part of a patient interface having a wall that at least partially encloses a volume of space, the air in the volume being pressurized to exceed atmospheric pressure in use. The shell may form part of the wall of the mask plenum chamber.

Seal: When used as a noun ("seal") it can refer to a structure, and when used as a verb ("seal") it can refer to an effect. Two elements can be constructed and/or arranged to "seal" or achieve a "sealing" effect between them without the need for a separate "sealing" element itself.

Shell: A shell is taken to mean a curved, relatively thin structure that has bending, tensile and compressive stiffness. For example, the curved structural wall of a mask may be a shell. In some forms, the shell may be faceted. In some forms, the shell may be airtight. In some forms, the shell may not be airtight.

Stiffener: Stiffener is taken to mean a structural component designed to increase the bending stiffness of another component in at least one direction.

Strut: A strut is taken to mean a structural component designed to increase the compression resistance of another component in at least one direction.

Swivel (noun): A subassembly of components configured to rotate, preferably independently, about a common axis, preferably under low torque. In one form, the swivel may be configured to rotate through an angle of at least 360 degrees. In another form, the swivel may be configured to rotate through an angle of less than 360 degrees. When used in the context of an air delivery conduit, the subassembly of components preferably includes a mating cylindrical conduit. In use, there is little leakage of air flow from the swivel.

Tie (noun): A structure designed to resist tension.

Venting: (noun): A structure that allows airflow to the ambient air inside a mask or conduit, allowing clinically effective flushing of exhaled gases. For example, flow rates of about 10 liters/minute to about 100 liters/minute may be used for clinically effective flushing, depending on mask design and treatment pressure.
5.7.3 Shape of structure

Products of the present technology may include one or more three-dimensional mechanical structures (e.g., a mask cushion or impeller). The three-dimensional structures may be bounded by two-dimensional surfaces. These surfaces may be differentiated with labels to describe the orientation, location, function, or some other characteristic of the associated surfaces. For example, the structures may include one or more of a front surface, a back surface, an interior surface, and an exterior surface. In another example, the seal-forming structure may include a face-contacting (e.g., exterior) surface and a separate non-face-contacting (e.g., lower or interior) surface. In another example, the structure may include a first surface and a second surface.

To facilitate the description of the shape and surfaces of a three-dimensional structure, we first consider a cross section at a point p through the surface of the structure. See Figures 3B-3F. Figures 3B-3F show an example cross section at a point p on the surface, and an example of the resulting planar curve. Figures 3B-3F also show the outward normal vector at p. The outward normal vector at p points away from the surface. In some examples, the surface is described from the perspective of a fictional little person standing upright on the surface.
5.7.3.1 Curvature in one dimension

The curvature of a plane curve at p can be described as having a sign (e.g., positive, negative) and a magnitude (e.g., 1/radius of the circle tangent to the curve at p).

Positive curvature: If the curve at p bends towards the outward normal, the curvature at that point is taken to have a positive value (if our imaginary little person were to walk away from point p, he would have to walk uphill). See Figure 3B (relatively large positive curvature compared to Figure 3C) and Figure 3C (relatively small positive curvature compared to Figure 3B). Such curves are often called concave.

Zero curvature: If the curve at p is a straight line, the curvature is taken as zero (if this imaginary little person walks away from point p, he can walk on a horizontal surface that is neither pointing up nor down). See Figure 3D.

Negative curvature: If the curve at p bends away from the outward normal, the curvature at that point and in that direction is taken to have a negative value (if this imaginary little person were to walk away from point p, he would have to walk downhill). See Figure 3E (relatively small negative curvature compared to Figure 3F) and Figure 3F (relatively large negative curvature compared to Figure 3E). Such curves are often called convex.
5.7.3.2 Two-dimensional surface curvature

The description of a shape at a given point on a two-dimensional surface according to the present technique may include multiple perpendicular cross sections. The multiple cross sections may cut the surface in a plane that contains the outward normal (the "normal plane"), and each cross section may be taken in a different direction. Each cross section results in a plane curve with a corresponding curvature. The different curvatures at the point may have the same sign or different signs. Each of the curvatures at the point has a (e.g., relatively small) magnitude. The plane curves in Figures 3B-3F may be examples of such multiple cross sections at a particular point.

Principal curvature and direction: The directions in the normal plane where the curvature of the curve has its maximum and minimum values are called the principal directions. In the example of Figures 3B-3F, the maximum curvature occurs in Figure 3B and the minimum occurs in Figure 3F, so Figures 3B and 3F are cross sections in the principal directions. The principal curvature at p is the curvature in the principal direction.

Surface region: A collection of connected points on a surface. This set of points within a region may have similar properties (e.g., curvature or sign).

Saddle region: A region where the principal curvatures at each point have opposite signs (i.e., one positive sign and the other negative sign) (depending on the direction a hypothetical person who could be walking uphill or downhill would be facing).

Dome area: A region in which the principal curvatures at each point have the same sign (either both positive ("concave dome") or both negative ("convex dome")).

Cylindrical region: A region in which one principal curvature is zero (or, for example, zero within manufacturing tolerances) and the other principal curvature is non-zero.

Planar region: A region of a surface where both principal curvatures are zero (or are zero within a manufacturing tolerance, for example).

Surface edge: the boundary or limit of a surface or area.

Path: In certain forms of the technology, a "path" is taken to mean a path in the mathematical-topological sense (e.g., a continuous space curve from f(0) to f(1) on a surface). In certain forms of the technology, a "path" may be described as a route or course that includes, for example, a set of points on a surface. (A hypothetical person's path is a place to walk on a surface, similar to a path in a garden).

Path Length: In certain forms of the present technology, "path length" is taken to refer to the distance along the surface from f(0) to f(1) (i.e., the distance along a path on the surface). There may be more than one path between two points on a surface, and such paths may have different path lengths. (The path length of a fictional person is the distance walked along a path on the surface).

Straight-line distance: Straight-line distance is the distance between two points on a surface, but does not take the surface into account. On a planar area, there is a distance on the surface edge that has the same path length as the straight-line distance between two points on the surface. On a non-planar surface, there cannot be a path that has the same path length as the straight-line distance between two points. (For a fictional person, straight-line distance corresponds to the distance "as the crow flies".)
5.7.3.3 Space Curves

Space Curve: Unlike a plane curve, a space curve does not necessarily lie in any particular plane. A space curve may be closed, i.e., it has no end point. A space curve may be considered a one-dimensional piece of three-dimensional space. A fictional character walking on a strand of DNA helix walks along a space curve. A typical human left ear includes a left-handed helix (see FIG. 3Q). A typical human right ear includes a right-handed helix (see FIG. 3R). FIG. 3S shows a right-handed helix. The edges of structures (e.g., the edges of a membrane or impeller) may trace a space curve. In general, a space curve may be described by the curvature and twist at each point on the space curve. Twist is a measure of the way the curve emanates from the plane. Twist has a sign and a magnitude. The twist at a point on a space curve may be characterized with respect to the tangent, normal, and binormal vectors at that point.

Tangent unit vector (or unit tangent vector): For each point on a curve, the vector at that point specifies the direction and magnitude from that point. A tangent unit vector is a unit vector that points in the same direction as the curve at that point. If a fictional character was flying along a curve and fell off his vehicle at a particular point, the direction of the tangent vector is the direction he would be traveling.

Unit normal vector: As our fictional character moves along the curve, this tangent vector itself changes. The unit vector that points in the same direction as the tangent vector is changing is called the unit principal normal vector. It is perpendicular to the tangent vector.

Binormal unit vector: The binormal unit vector is perpendicular to both the tangent vector and the principal normal vector. Its direction can be determined by the right-hand rule (see, for example, Figure 3P) or the left-hand rule (Figure 3O).

Contact plane: A plane that contains a unit tangent vector and a unit principal normal vector. See Figures 3O and 3P.

Torsion of a space curve: The torsion at a point of a space curve is the magnitude of the rate of change of the binormal unit vector at that point. It measures the degree of deviation of the curve from the tangential plane. A space curve that lies in the plane has zero torsion. If the space curve deviates from the tangential plane by a relatively small amount, the magnitude of torsion of the space curve is relatively small (e.g., a gently sloping spiral path). If the space curve deviates from the tangential plane by a relatively large amount, the magnitude of torsion of the space curve is relatively large (e.g., a steeply sloping spiral path). With reference to FIG. 3S, the magnitude of torsion near the top coil of the spiral of FIG. 3S is greater than the magnitude of torsion of the bottom coil of the spiral of FIG. 3S because T2>T1.

Referring to the right-hand rule in Figure 3P, a space curve that bends towards the right-hand binormal can be considered to have a positive right-hand twist (e.g., a right-hand spiral as shown in Figure 3S). A space curve that bends away from the right-hand binormal can be considered to have a negative right-hand twist (e.g., a left-hand spiral).

Similarly, with reference to the left-hand rule (see FIG. 3O), a space curve oriented in a left-handed binormal direction can be considered as having a positive left-handed twist (e.g., a left-handed spiral), where a positive left-handed direction thus corresponds to a negative right-handed direction, see FIG. 3T.
5.7.3.4 Holes

Surfaces can have one-dimensional holes (e.g., holes bounded by a plane or space curve). For thin structures that contain holes (e.g., membranes), the structure can be described as having one-dimensional holes. See, for example, how the one-dimensional holes in the surface of the structure shown in Figure 3I are bounded by a plane curve.

A structure may have a two-dimensional hole (e.g., a hole bounded by a surface). For example, an inflatable tire has a two-dimensional hole bounded by the tire inner surface. In another example, a bladder with a cavity for air or gel may have a two-dimensional hole. See, for example, the cushion of FIG. 3L and the exemplary cross-section of FIG. 3L in FIGS. 3M and 3N, where the inner surface bounding the two-dimensional hole is shown. In yet another example, a conduit may include a one-dimensional hole (e.g., at its inlet or its outlet) and may include a two-dimensional hole bounded by the inner surface of the conduit. See also the two-dimensional hole through the structure shown in FIG. 3K and bounded by a surface as shown.
5.8 Other precautions

A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the reproduction by any person of this patent document or this patent disclosure by facsimile, for purposes as set forth in the Patent and Trademark Office patent file or records, but reserves all copyright rights thereto for all other purposes.

Unless otherwise clearly indicated from the context and unless a range of values is provided, it is understood that each intervention value between the upper and lower limits of the range and any other stated or intervention value in the stated range is encompassed by the technology. The upper and lower limits of these intervention ranges that are independently included in the intervention range are also encompassed by the technology if they specifically exceed the limits in the stated range. If the stated range includes one or both of these limits, then ranges exceeding either or both of these stated limits are also encompassed by the technology.

Furthermore, when a value or values are embodied herein as part of the present technology, unless otherwise indicated, it is understood that such values may be approximated and may be used to any appropriate significant figures to the extent practical technical implementation permits or requires.

Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this technology belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of this technology, a limited number of exemplary methods and materials are described herein.

Although certain materials are described as being suitable for use in the construction of components, obvious alternative materials having similar properties may be substituted. Further, unless stated to the contrary, any and all components described herein are understood to be manufacturable and therefore may be manufactured collectively or separately.

Please note that as used herein and in the appended claims, the singular forms "a," "an," and "the" include their plural equivalents unless the context clearly indicates otherwise.

All publications cited herein are incorporated by reference to disclose and describe the methods and/or materials to which they are the subject. Publications cited herein are provided solely for their disclosure prior to the filing date of this application. Nothing herein should be construed as an admission that the present technology does not antedate such publications by virtue of prior patents. Further, the dates of publications cited may be different from the actual publication dates, which may need to be independently confirmed.

The terms "comprises" and "comprising" should be construed to refer to elements, components, or steps in a non-exclusive sense, indicating that a described element, component, or step may be present in, utilized with, or combined with other elements, components, or steps not specifically described.

The headings used in the detailed description are for the convenience of the reader and should not be used to limit the content found in the disclosure or claims as a whole. These headings should not be used in interpreting the scope of the claims or the limitations of the claims.

Although the technology herein has been described with reference to specific examples, it should be understood that these examples are merely illustrative of the principles and applications of the technology. In some cases, terms and symbols may indicate specific details that are not necessary for the practice of the technology. For example, the terms "first" and "second" (etc.) are used, but unless otherwise specified, these terms are not intended to indicate any order, but are used to distinguish between separate elements. Furthermore, although the process steps in the method may be described or illustrated in an order, such order is not required. Those skilled in the art will recognize that such order may be changed and/or aspects thereof may be performed simultaneously or even synchronously.

Thus, it should be understood that numerous variations in the illustrative embodiments are possible and other arrangements may be devised without departing from the spirit and scope of the present technology.

[List of reference numbers]
5.9 List of References Feature Item Number Patient 1000
Bedmate 1100
Patient Interface 3000
Seal forming structure 3100
Plenum Chamber 3200
Stabilizing Structure 3300
Ventilation 3400
Connection port 3600
Forehead support 3700
RPT Device 4000
Air Circuit 4170
Humidifier 5000
Water Reservoir 5110
Reservoir Base 5112
Reservoir Lead 5114
Compliant Division 5116
Entrance 5118
Heating plate 5120
Exit 5122
Water Reservoir Dock 5130
Orifice 5138
Base upper body 5146
Base bottom plate 5148
Sidewall 5149.1
Bottom wall 5149.2
Hole 5149.3
Thin Film 5152
First aspect 5152.1
Second aspect 5152.2
Hinge 5158
Cavity 5160
Dock Air Outlet 5168
Dock air inlet 5170
Humidifier outlet 5172
Rib 5175
Humidifier Converter 5210
Air pressure sensor 5212
Flow Converter 5214
Temperature Sensor 5216
Humidity Sensor 5218
Inner lip 5224
Outer lip 5226
Heating element 5240
Humidifier Controller 5250
Central Humidifier Controller 5251
Heating Element Controller 5252
Air Circuit Controller 5254

Claims (25)

1. A water reservoir for an apparatus for generating a flow of breathable gas and humidifying the flow of breathable gas, the water reservoir configured for removably receipt by a water reservoir dock of the apparatus, the water reservoir dock comprising a heating plate, the water reservoir comprising:
a reservoir base including a bottom wall and a side wall forming a cavity configured to hold a volume of liquid;
a conductive portion provided on the reservoir base, at least a portion of the conductive portion adapted to thermally engage the heating plate when the water reservoir is removably received by the water reservoir dock to allow thermal transfer of heat from the heating plate to the volume of liquid in use; and
Including,
the conductive portion includes a thin film including an elastomeric material;
the membrane includes a first side including at least a portion configured to form a bottom inner surface of the water reservoir exposed to the volume of liquid, and a second side opposite the first side, the second side including at least a portion configured to form a bottom exposed outer surface of the water reservoir exposable to the heating plate to enable thermal engagement with the heating plate when the water reservoir is removably received by the water reservoir dock;
at least a portion of the bottom wall and the side wall of the reservoir base form an inner surface of the water reservoir exposed to the volume of liquid;
the bottom wall of the reservoir base includes a hole;
the membrane is secured to hermetically cover the hole;
A peripheral edge of the membrane extends beyond an edge of the hole such that the membrane overlaps at least a portion of the inner surface of the bottom wall. 2. The water reservoir of claim 1, wherein the peripheral edge of the membrane extends to one or more of the side walls of the reservoir base such that the membrane overlaps at least a portion of an inner surface of the one or more of the side walls of the reservoir base. 3. The water reservoir of claim 1 or 2 , wherein the membrane comprises a wall thickness that is less than the wall thicknesses of the bottom wall and the side walls of the reservoir base. A water reservoir according to any one of claims 1 to 3 , wherein the membrane is provided as a separate and distinct structure from the reservoir base. A water reservoir as described in any one of claims 1 to 4, wherein the second side of the membrane provides a contact surface constructed and arranged to directly engage the heating plate when the water reservoir is removably received by the water reservoir dock. The water reservoir of claim 1 , wherein the membrane comprises a preformed structure that is secured to the reservoir base. The water reservoir according to any one of claims 1 to 6 , wherein the thin film comprises silicone. A water reservoir according to any one of claims 1 to 7 , wherein the membrane is generally planar. The water reservoir of any one of claims 1 to 8 , further comprising one or more ribs constructed and arranged to extend over the membrane. The reservoir base includes a base upper body and a base lower plate;
The water reservoir according to claim 1 , wherein the base upper body and the base lower plate together with the membrane form the cavity. The water reservoir of claim 10 , further comprising a sealing element between the base upper body and the base lower plate to prevent water ingress. The water reservoir of any one of claims 1 to 11 , further comprising a reservoir lid, the reservoir lid being movably connected to the reservoir base such that the water reservoir can be converted between an open configuration and a closed configuration. the reservoir lid comprises an inlet configured to receive a flow of the breathable gas into the water reservoir and an outlet configured to deliver the flow of the breathable gas from the water reservoir in a humidified state;
The water reservoir of claim 12 , wherein the inlet and the outlet face in a common direction. A water reservoir according to any one of claims 1 to 13 , wherein the membrane has a wall thickness of less than about 0.5 mm. A water reservoir according to any one of claims 1 to 14 , wherein the membrane is shaped to fit and overlap the bottom wall and/or the side wall of the reservoir base. The water reservoir according to any one of claims 1 to 15 , wherein the thin film comprises one or more additives to improve thermal conductivity. A water reservoir according to any one of claims 1 to 16 , wherein the thin film comprises a ceramic powder additive. The water reservoir of any one of claims 1 to 17 , wherein the thin film comprises a metal powder additive. The water reservoir according to any one of claims 1 to 18 , wherein the membrane comprises multiple layers. 20. The water reservoir of claim 19 , wherein the membrane comprises a metal layer and at least one plastic layer. 21. The water reservoir of claim 20 , wherein the at least one plastic layer comprises a plastic layer on each side of the metal layer. A water reservoir according to any preceding claim, wherein the membrane comprises a coating of a thermally conductive material applied to one side of the membrane. 1. An apparatus for humidifying a stream of breathable gas, comprising:
Water reservoir dock,
A water reservoir according to any one of claims 1 to 22 , provided in the water reservoir dock;
An apparatus comprising: 24. The device of claim 23 , wherein the water reservoir dock forms a cavity to at least partially receive the water reservoir. 25. The apparatus of claim 23 or 24 , wherein the water reservoir dock includes a heating plate adapted to thermally engage a conductive portion provided on the water reservoir.

Images